Guitar fretboard for a four-string bass guitar



FIG. 1 is a perspective view of a guitar fretboard for a four-string bass guitar, showing my new design in an exemplary environment.

FIG. 2 is a side view thereof;

FIG. 3 is a top view thereof; and,

FIG. 4 is a second side view thereof.

The broken lines are included for the purpose of illustrating the environmental structure and form no part of the claimed design. 

CLAIM An ornamental design for a guitar fretboard for a four-string bass guitar, as shown and described. 